Jacuzzi Whirlpool Bath HTA Jet Nut for 4-1/2" Hole Size (1645000) is a replacement nut for compatible Jacuzzi Whirlpool Bath HTA jet installations requiring a 4-1/2" hole size. It is intended for service work on compatible Jacuzzi Whirlpool Bath equipment where matching the original part style, size, and application is important for a clean repair. This part can help restore the fit, function, or appearance of the related assembly without replacing more of the system than necessary.Use this part to secure the jet assembly during bath or spa service. Verify hole size and HTA jet compatibility before ordering. For best results, compare the existing component, equipment model, measurements, and part number before ordering or beginning installation. Replacement part for compatible Jacuzzi Whirlpool Bath equipment Designed for jet parts service applications Helps restore proper fit, operation, or assembly condition Useful for repair, rebuild, replacement, or routine maintenance work Verify part number and compatibility before purchase