The LTT20B is for nail- or bolt-on applications. The 3" nail spacing makes the LTT20B suitable for wood I-joists if 10dx1 1/2" nails are substituted for the specified 16d's. If a 1/2" or 5/8" anchor bolt is used for the LTT20B, add a standard cut washer to the seat. No additional washer is required for a 3/4" anchor bolt. Requires "Motor Freight" shipping. Please select Motor Freight option at checkout and Loyola customer service will email or call you with shipping charges before charging your credit card. Availability: Usually ships in 2-3 business days. You can also call us at; 1-800-937-9021 x106 or 1-757-498-6118 x106 LTT20B - EACHES PRICE$15.25