NON-TILT WINDOW COMPATIBILITY – Designed specifically for non-tilt residential windows, the Series 100 Spirex features a 5/8" spiral tube (also compatible with many 9/16" systems). This model measures 27" in length with a Blue Tip calibrated for 12-31 lbs sash weights, providing dependable operation and balanced sash support. MULTIPLE SIZES AVAILABLE – Offered in lengths from 10" to 51" with calibrated weight ranges from 4–30 lbs. Select the exact length and capacity to match your window. Balances are sold individually; contact WRS if your size does not match a standard option. DURABLE STEEL CONSTRUCTION – Built with a rugged steel spiral rod and pencil-style tube, the Series 100 provides reliable sash support and consistent performance for years of daily use EASY TO MEASURE & INSTALL – Measure only the metal tube (exclude tip/spiral) and confirm the tube diameter. Direct-fit replacement installs easily with common hand tools. Pivot locking shoes not included. 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. The 100 Series is a standard spiral window balance for non-tilt/sideload window applications. This balance is designed for residential and commercial window applications. These balances feature a 5/8" diameter tube and lengths ranging from 7" to 51" and weight capacities from 4lbs to 30lbs you're sure to find the spiral window balance to fit your needs.