Caldwell Series 300 Block & Tackle Window Balance – 5/8″ Channel, 19″ Length, Stamp 18-1 (5-8 lbs), Non-Tilt Side-Load Replacement Hardware – Heavy-Duty for Residential & Commercial Windows
*Price sourced from Amazon.com. Last updated 2026-07-22. Price and availability subject to change.
Bottom line: The Caldwell Series 300 Block & Tackle Window Balance – 5/8″ Channel, 19″ Length, Stamp 18-1 (5-8 lbs), Non-Tilt Side-Load Replacement Hardware – Heavy-Duty for Residential & Commercial Windows is a niche pick — read recent reviews before buying in the retro software & media category, priced around $8.03. Read recent reviews carefully before committing.
SpecPicks Verdict
SpecPicks classifies WRS Caldwell Series 300 Block & Tackle Window Balance – 5/8″… as a niche pick — read recent reviews before buying in the retro software & media category, based on our editorial and benchmark analysis and our ranking model that weights rating × review-volume × price-fit. WRS's positioning sits within the broader category mid-tier. Use the Compare tool to put it side-by-side with two or three close alternatives before clicking through to Amazon.
Common buyer scenarios for retro software & media of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the Amazon listing before purchase. Prices, stock, and Prime eligibility update directly from Amazon's catalog and may have moved since this page was last verified.
Pros & Cons
Pros
- ✓ Backed by WRS's warranty and support channels
- ✓ Ships via Amazon with Prime eligibility and the standard returns policy
Cons
- ✗ Confirm socket / form-factor / power-rating compatibility against your build before ordering
- ✗ Price, stock, and Prime eligibility update from Amazon and may have changed since this page was last verified
Key Features
- ENGINEERED FOR NON-TILT WINDOWS – Designed for side-load, non-tilt window systems with a standard 5/8″ metal channel, commonly used in vinyl and aluminum single- or double-hung frames. This balance measures 19" inches in length and supports 5-8 lbs sashes. Each balance arrives pre-assembled with top and bottom guides attached, so installation is fast and frustration-free—no special tools required.
- AVAILABLE IN LENGTHS FROM 8″ TO 49″ (3 TO 44 LB RANGE) – The Series 300 fits nearly all non-tilt window sizes, from light residential sashes to heavy commercial frames. Covers a complete range of lengths and weight ratings for versatile use. Each balance is precision-tested for smooth, reliable performance and long-term durability. Sold individually; accessories and hardware not included. Contact WRS if your exact size isn’t listed.
- SMOOTH, SAFE & SECURE OPERATION – The Series 300’s precision pulley and spring system balances the sash to prevent slamming or sticking, keeping windows steady at any height. Designed for quiet, reliable performance in homes, schools, and offices where safety and ease of use matter every day.
- HEAVY-DUTY GALVANIZED STEEL CONSTRUCTION – Crafted from high-strength galvanized steel for long-term durability and corrosion resistance. Precision pulleys and springs maintain smooth lift through thousands of cycles, ensuring reliable performance for years of daily use. Built tough for pros yet simple enough for DIY installation.
- TRUSTED SINCE 1989 – WRS Window Repair Systems has over 30 years of experience supplying reliable, high-quality hardware. Trusted nationwide by homeowners, contractors, schools, and property managers for dependable repairs and long-lasting performance.
Full Specifications
| Size | 18-1 (5-8 lbs) |
|---|---|
| Brand | WRS |
| Color | Metal |
| Style | American |
| Weight | 44 lb |
| Part Number | 01-30018-1 |
| Batteries Required? | No |
| Item Package Quantity | 1 |
Ready to buy?
WRS Caldwell Series 300 Block & Tackle Window Balance – 5/8″ Channel, 19″ Length, Stamp 18-1 (5-8 lbs), Non-Tilt Side-Load Replacement Hardware – Heavy-Duty for Residential & Commercial Windows is available on Amazon with Prime shipping and the full Amazon returns policy. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.
*Price sourced from Amazon.com. Last updated 2026-07-22. Price and availability subject to change.
Related Retro Software & Media
More guides & deep dives from the SpecPicks archive
Browse all articles & guides →- Best 1440p Gaming GPUs in 2026
- How to Build a Windows 98 Retro PC in 2026
- RTX 4070 Super vs RX 7800 XT — Which to Buy in 2026
- Best Retro Handhelds in 2026 — From $35 to $500
- Best Budget Gaming PC Build 2026 — ~$1,000 ($800 on Sale)
- Emulation Hardware in 2026: FPGA, Software, and Cart-Reader Ecosystems
- The Complete Voodoo5 5500 AGP Driver Guide (2026 Edition)
More reviews from the SpecPicks archive
Browse all reviews →- Best Controller for Retro Emulation on PC: 8BitDo, GameSir, DualSense
- Raspberry Pi 5 IOMMU Support Is Landing in the Mainline Linux Kernel
- Best SSD for PS5 and Console-PC Hybrid Setups in 2026
- Best 16GB GPU for Local LLM 2026
- Best CPU Coolers for Ryzen in 2026: 5 Tested Picks
- Best Capture Device for Recording Retro Consoles and Old PCs in 2026
- Best GPU for AI code generation in 2026
- SATA vs NVMe for a Ryzen 5800X Gaming Build: Does It Matter?
- Best Gaming Monitor for 1440p in 2026
- Best CompactFlash and IDE/SATA-to-USB Storage Gear for Retro PC Builds in 2026
- vLLM 0.21 Adds Intel GPU Support: What It Means for Budget AI Rigs
- Best AMD CPUs for Gaming in 2026: Top Ryzen Picks
- Best PlayStation Controller for PC Gaming in 2026
- Best SSD for PS5 Storage Expansion Under $100 (2026)
- SNES Classic vs Sega Genesis Mini in 2026: Which Is Worth It?
- Best SATA SSD to Revive an Old Gaming PC in 2026
- Forza Horizon 6 Boots in 4 Seconds with Advanced Shader Delivery
- Intel llm-scaler-vLLM 1.4 with Arc Pro B70: Local Inference vs RTX 3060 12GB
- Logitech G29 / G920 Not Detected on Windows 11: Step-by-Step Driver Fix Guide (2026)
- Intel Nova Lake-S adds two 22-core gaming-cache SKUs
- Best AM4 CPU to Pair With an RTX 3060 12GB in 2026
- Best Controller for PC Retro Gaming (2026)
- ComfyUI on an RTX 3060 12GB: Real Image-Gen Throughput in 2026
- Ryzen 5 5600G vs Ryzen 7 5700X: Best Budget Build CPU 2026