In the USA, CANBERRA offers Radioisotope Purchase Certificates or "coupons" which may be redeemed upon request for any of the standard uncalibrated 1" solid or uncalibrated liquid sources. These coupons may be purchased individually or in a book of five. When you require a specific radioisotope product, simply check off the requested model number, indicate the desired date of delivery, and mail the certificate to us. We will process your order and ship the source to arrive when needed. Please allow enough time for the coupon to reach us and for the return shipment to reach you. Normally 12-15 days is sufficient. Prices for Radioisotope Coupons are the same as for the source models listed plus shipping and handling. Coupons are valid for one year from the date of purchase.